Mold for casting refractories



Oct. 2.7, 1931. w SCHROEDER 1,829,114

MOLD FOR CASTING REFRACTORIES Filed July 9, 1930 B l- EEJCL- C o u u 1 u1| n n HHHI nun H gwoewto'a Frederic w/shroedeg @W cl Patente Oct. 27,1931 UNITED, STATES PATENT OFFICE FREDEBIO W. SGEROEDER, OF LOUISVILLE,KENTUCKY,- ASSIGNOR 'I'O CO-RHART RE- FRAGTORIES COMPANY, OF LOUISVILLE,KENTUCKY, A CORPORATION OF DELA- WARE MOLD FOR CASTING REFRACTORIES.

Application filed July 9, 1930. Serial No. 466,788

This invention has for its object to provide a suitable mold structurein which refractories of'the character described in the patent to'Fulcher, No. 1,615,750, may be cast. As described in that patent, themolten material (a mixture essentially consisting of alumina and silica)is poured in a form built up of baked sand slabs, which are buried insil-ocel to retard heat losses in the cast article. In carrying out theprocess according to the disclosure of that perienced in that t e slabsbend under the internal pressure of the molten material, so that sidesof the cooled 'blocks were found to bulge, which was objectionable inbuilding them into a wall. In an attempt to overcome this bulging,recourse was had to the scheme shown in the Fulcher Patent 1,700,288, inwhichv the baked sand slabs were backed by supports of insulatingbricks, but it was found that the slabs bulged between the bricksupports. Further efforts to avoid the bulging involved supporting theslabs by a backing of boards throughout the entire area of the slabs,the boards being held in position by wedges, etc. While this last schemewas successful, in that it prevented bulging, it was expensive inmaterial and labor. All these difficulties have been overcome by theinvention described herein, in which the baked sand slabs are assembledinto a mold of the desired shape within a rigid flask,

of a shape and size adapted to receive the assembled mold, and the spacebetween the exterior of the mold slabs, and the interior of walls of theflask is packed with granular material. Under these conditions it hasbeen found that bulging is prevented, and that after the casting hasset, the flask may be lifted from around the mold as formed by theslabs, the interposed granular material permitting this. My inventiontherefore consists in the construction, arrangement and combination ofthe parts of which it is comprised, as will be hereinafter described andclaimed.

Referring to the accompanying drawings in which corresponding parts aredesignated by similar marks of reference,

atent, difficulty was ex- Figure 1 is a plan view of a mold structureembodying this invention.

Figure 2 is a transverse vertical central section thereof.

Figure 3 is a plan view of a modified form of mold structure alsoembodying this invention.

Figure 4 is a detail of the spreader shown in Figure 3.

As' represented in all the figures, the mold proper is made up of theside slab A, the end slabs B and B, and the cover slab C, having a gateopening therein. These slabs are of baked sand prepared in accordancewith the disclosure of the Fulcher patent, 1,615,750. In all thefigures, the mold as thus formed, is enclosed in a suitable rigid flask0, con-- sisting of side and end walls and preferably made of cast iron.

The flask in Figure 1 is of a size and shape to snugly receive the moldassembly, a space 0 of about an eighth 'of an inch being left betweenthe inner face of the one and the outer face of the other; This space isfilled with freely flowing sand. The sand readily accommodates itself tothe irregularities in the surface of the slabs and of the flask, andsupports the former throughout their area against the pressure of themolten material. At the same time the sand acts as a lubricant, as itwere, when, after the casting is set, the flask is lifted away from themold proper.

In Figures 3'and 4, an arrangement is shown in which the flask is longerthan the mold. In this case a cast iron spacer D is laid across of theflask,-and supported by brick E from the end thereof, the spacebebetween the slabs and the inner surface of the walls of the flask. s2. In a device of the character described, the combination of a moldcomposed of baked slabs, of a flask within which the mold fits, and alayer of freely flowing sand interposed between the slabs and the innersurface of the walls of the flask, such layer of sand being suflicientlythin as to prevent appreciable distortion" of the said slabs,substantially as described.

In testimony whereof I hereunto aflix -my signature.

' FREDERIC SCHRQEDER.

